[Libva] libva introductory article for newbies?

[Xiang, Haihao]

On Wed, 2013-02-06 at 21:34 +0400, Rinat Ibragimov wrote: 
> Среда,  6 февраля 2013, 13:24 +08:00 от "Xiang, Haihao" <haihao.xiang at intel.com>:
> >On Tue, 2013-02-05 at 23:41 +0400, Ibragimov Rinat wrote: 
> >> Hi,
> >> 
> >> During making attempts to use VAAPI I faced with couple of difficulties
> >> and then realized I have no high-level understanding of how it should
> >> be used. Philosophy of libva, if you like. Is there exists some
> >> introductory article about?
> >
> >You can build the documentation which contains some pseudo code.
> 
> Thank you. First I tried to enable doxygen output, and got empty result, as master branch
> did not have all required formatting. Staging branch contains all I need.
> 
> >
> >> 
> >> I don't understand why in i965 driver vaQueryImageFormats returns formats
> >> in YUV-colorspace only (YV12, I420, NV12) but vaCreateImage have some code
> >> with BGRA too. 
> >
> >The image formats returned from vaQuerySubpictureFormats() are valid to
> >vaCreateImage()
> >
> 
> One more question. 
> Is it correct that one can not display RGB VAImage other than rendering it to YUV surface with
> vaPutImage and then calling vaPutSurface? This will introduce slight quality loss and I would
> prefer to avoid that.
> 

Yes for the current driver. 

> --
> Rinat
>